1. Technical Field
The present disclosure relates to three-dimensional reconstruction and, more specifically, to three-dimensional reconstruction of the esophagus.
2. Discussion of Related Art
Cardiac dysrhythmia (arrhythmia) is characterized by abnormal electrical activity in the heart. Cardiac dysrhythmia may cause the heart to beat too fast, too slow, or irregularly. Cardiac dysrhythmia can be a life-threatening condition. Atrial fibrillation is a particularly common form of cardiac dysrhythmia. Here, the upper two chambers of the heart, known as atria, beat at irregular intervals. This irregular beating may be caused by abnormal electrical impulses that may be produced by diseased or damaged cardiac tissue. As chronic atrial fibrillation, and other forms of cardiac dysrhythmia may place patients at greater risk for certain conditions such as stroke, catheter ablation may be used to treat cardiac dysrhythmia such as atrial fibrillation.
In catheter ablation, catheters are inserted into a patient's blood vessels and then advanced towards the heart. When contact is made with cardiac tissue that is responsible for generating abnormal electrical impulses, the catheter is used to destroy the responsible tissue so that normal electrical impulse may be restored. Ablation of the responsible tissue is generally performed using heat. Pulmonary vein ablation (also called pulmonary vein antrum isolation or PVAI), is a common treatment for atrial fibrillation.
Due to the proximity of the left atrium and the esophagus, and owing to the fact that both the esophagus and the heart are in relative motion, heat generated during catheter ablation of the left atrium carries the risk of generating a left atrial-esophageal fistula. Such a complication is particularly serious and is associated with a high mortality rate. Reducing the ablation temperature and power settings along the posterior left atrial wall has been suggested to reduce the risk of this complication. Other approaches include esophageal temperature monitoring and the use of intracardiac echo. Identification of the esophagus' location and avoiding lesions directly overlying the esophagus has been proposed as well. A particularly cost-efficient approach is to use orally administered barium paste to visualize the esophagus under X-ray during a case. While this is a simple and inexpensive technique, the difficulty with this approach is that the paste does not remain in the esophagus throughout the entire ablation procedure.
Accordingly, once the barium paste has cleared the esophagus, visualization of the esophagus by fluoroscope may be lost and the patient may be placed at a greater risk of atrio-esophageal fistula.